Epidemiological cut-off values forflavobacterium psychrophilummic data generated by a standard test protocol
Smith, P Endris, R Kronvall, G Thomas, V Verner-Jeffreys, D Wilhelm, C Dalsgaard, I
Smith, P
Endris, R
Kronvall, G
Thomas, V
Verner-Jeffreys, D
Wilhelm, C
Dalsgaard, I
Publication Date
2014-12-26
Keywords
clsi protocols, epidemiological cut-off values, flavobacterium psychrophilum, mic, normalized resistance interpretation, vet03/04-s2, rainbow-trout fry, normalized resistance interpretation, oncorhynchus-mykiss walbaum, disc diffusion data, antimicrobial resistance, aeromonas-salmonicida, quinolone resistance, antibiotic susceptibilities, gyra mutations, fish
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Article
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Citation
Smith, P; Endris, R; Kronvall, G; Thomas, V; Verner-Jeffreys, D; Wilhelm, C; Dalsgaard, I (2014). Epidemiological cut-off values forflavobacterium psychrophilummic data generated by a standard test protocol. Journal of Fish Diseases 39 (2), 143-154
Abstract
Epidemiological cut-off values were developed for application to antibiotic susceptibility data for Flavobacterium psychrophilum generated by standard CLSI test protocols. The MIC values for ten antibiotic agents against Flavobacterium psychrophilum were determined in two laboratories. For five antibiotics, the data sets were of sufficient quality and quantity to allow the setting of valid epidemiological cut-off values. For these agents, the cutoff values, calculated by the application of the statistically based normalized resistance interpretation method, were <= 16 mg L-1 for erythromycin, <= 2 mg L-1 for florfenicol, <= 0.025 mg L-1 for oxolinic acid (OXO), = <= 0.125 mg L-1 for oxytetracycline and <= 20 (1/19) mg L-1 for trimethoprim/sulphamethoxazole. For ampicillin and amoxicillin, the majority of putative wild-type observations were 'off scale', and therefore, statistically valid cut-off values could not be calculated. For ormetoprim/ sulphadimethoxine, the data were excessively diverse and a valid cut-off could not be determined. For flumequine, the putative wildtype data were extremely skewed, and for enrofloxacin, there was inadequate separation in the MIC values for putative wild-type and non-wild-type strains. It is argued that the adoption of OXO as a class representative for the quinolone group would be a valid method of determining susceptibilities to these agents.
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Publisher
Wiley-Blackwell
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Attribution-NonCommercial-NoDerivs 3.0 Ireland